Transformer isolated high voltage, high power amplifier systems capable of effectively driving loads such as, for example, servo motors, without transformer core gapping are not commonly available. Prior art amplifier systems use an A.C. coupled input signal to prevent undesirable transformer saturation. However, this arrangement does not remove the signal's D.C. component due to output stage offset, thereby necessitating gapping the transformer core and complicating the system. The prior art systems also use a capacitor in series with the transformer primary winding to prevent the aforenoted saturation. In high power applications this arrangement is not practical due to the size of the capacitor required.
At relatively low output voltage levels phase shift and cross over signal distortion can occur. Output control loops used to accommodate this distortion cause high signal unbalance in positive and negative half-cycle signal areas.
Accordingly, it is an object of the present invention to overcome the aforenoted disadvantages of prior art transformer isolated high voltage, high power amplifier systems and to provide a system which is simple in construction and has a reduced number of components.